Application of compound dephosphorization agent in municipal sewage treatment

1 Project Overview

The design scale of A domestic sewage treatment plant in hubei province is 20000m3/d, which adopts the multi-stage A/A/O improved process independently developed by the group company.  The effluent quality shall comply with the national urban Sewage discharge Grade A standard (GB18918-2002).  Among them, COD, ammonia nitrogen, total nitrogen and other indexes have reached the national discharge standards in high quality. However, due to the influence of incoming water quality, the total phosphorus (TP) in the biochemical effluent of the plant is high in the range of 0.9 ~ 1.0mg/L for a long time, and the pressure of the back-end efficient phosphorus removal section is doubled, and the cost of physical and chemical phosphorus removal is also high.

Our company was invited to screen the phosphorus removal agents for the efficient physical and chemical phosphorus removal section, and finally screened the best phosphorus removal agents, which were well received by customers.

2 Project Objectives

In view of the effluent quality of the plant complies with the national urban sewage discharge Grade A standard (GB18918-2002), the total phosphorus (TP) of the discharge outlet should be controlled less than 0.5mg/L. In view of the comprehensive consideration of environmental protection, safety and operation costs, the internal control index of the plant: the total phosphorus (TP) of the discharge outlet should be controlled within 0.3 ~ 0.35mg/L.

3 Solution

After the treatment with the selected compound dephosphorization agent, the total phosphorus (TP) in the effluent of the efficient sedimentation tank is kept between 0.2 and 0.35mg/L, which fully meets the requirements of the internal control index of the plant. At the same time, the single consumption of phosphorus removal agent is only about 18.5ppm, which is lower than the customer's expected single consumption of 20ppm, which perfectly solves the customer's operation problem.